musl-gcc: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/musl-gcc - from package: musl-tools

You may install the required package with command apt-get install {package}

Error in other languages:
musl-gcc: bevel nie gevind nie
musl-gcc: comandă negăsită
musl-gcc: comando não encontrado
musl-gcc: commande introuvable
musl-gcc: command not found
musl-gcc: käsku ei ole
musl-gcc: không tìm thấy lệnh
musl-gcc: komanda nerasta
musl-gcc: Kommando nicht gefunden.
musl-gcc: kommandot finns inte
musl-gcc: komut yok
musl-gcc: nie znaleziono polecenia
musl-gcc: níor aimsíodh an t-ordú
musl-gcc: no se encontró la orden
musl-gcc: no s'ha trobat l'ordre
musl-gcc: opdracht niet gevonden
musl-gcc: parancs nem található
musl-gcc: perintah tidak ditemukan
musl-gcc: príkaz nenájdený
musl-gcc: příkaz nenalezen
musl-gcc: команда не найдена
musl-gcc: командата не е открита
musl-gcc: 命令找不到
musl-gcc: コマンドが見つかりません